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## Re: [Help-gsl] Complex eigenvalues

 From: Andras Simon Subject: Re: [Help-gsl] Complex eigenvalues Date: Thu, 10 May 2007 13:05:47 -0500 User-agent: Microsoft-Entourage/11.3.3.061214

```OK, never mind, I just read the 1.9 version has this implemented first...

Thanks

On 5/10/07 1:01 PM, "Andras Simon" <address@hidden> wrote:

> Thanks, it cleared up some of the misunderstanding I had...
> Now the problem I run into is that the gsl_eigen_nonsymm()
> and similar functions are simply missing from the GSL distro
> I have....I use it on Mac OS 10.4.9, via fink, and it is
> Version 1.7-3. Did the gsl_eigen_nonsymm() appear in later
> versions ?
>
> Andras
>
>
> On 5/10/07 4:41 AM, "Hannes Basler" <address@hidden> wrote:
>
>> Hi,
>> all eigenvalues of a Hermitian Matrix are real, so there is no need
>> for complex eigenvalues if you use gsl_eigen_herm(). A symmetric
>> matrix is a special case of a hermitian matrix and has also only real
>> eigenvalues.
>> If you have a nonsymmetric real matrix you can use gsl_eigen_nonsymm
>> (), this function gives the eigenvalues in a gsl_vector_complex*.
>> At the moment there is no function to compute the eigenvalues of a
>> nonhermitian complex matrix in GSL.
>>
>> Cheers,
>> Hannes
>>
>> On May 10, 2007, at 9:21 AM, Andras Simon wrote:
>>
>>> Hi there,
>>>
>>>
>>> I have been searching the archives, but could not find the answer
>>> to this
>>> question: how to calculate the complex eigenvalues of a real or
>>> complex
>>> matrix ? I have tried gsl_eigen_herm() and gsl_eigen_symm(), but it
>>> appears
>>> as both functions assume that the eigenvalues are real (the type of
>>> eigenvalues vector is gsl_vector* type). I could not figure out how
>>> to get
>>> the complex eigenvalues into a gsl_vector_complex*.
>>> Any ideas ? Comments ?
>>>
>>> Any help is appreciated, I'm stuck ;(
>>>
>>>
>>> Thanks,
>>> Andras Simon
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> Help-gsl mailing list
>>> http://lists.gnu.org/mailman/listinfo/help-gsl
>>

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